Breaking water-in-oil emulsions



United States Patent BREAKING WATER-lN-OIL EMULSIONS Willard H.Kirkpatrick, Sugar Land, Tex., assignor to Visco Products Company,Houston, Tex., a corporation of Delaware No Drawing. ApplicationFebruary 27, 1956 Serial No. 567,728

10 Claims. (Cl. 252-331) This invention relates in particular to thetreatment of emulsions of mineral oil and water, such as petroleumemulsions commonly encountered in the production, handling and refiningof crude mineral oil, for the purpose of separating the oil from thewater. Also, the invention relates to the treatment of other water-inoil types of emulsions wherein the emulsions are produced artificiallyor naturally and the resolution of the emulsions presents a problem ofrecovery or disposal.

The present application is a continuation-in-part of my copendingapplication Serial No. 98,162 filed June 9, 1949, now abandoned, and acopending application Serial No. 250,013, filed October 5, 1951, nowabandoned.

Petroleum emulsions are in general of the water-in-oil type wherein theoil acts as a continuous phase for the dispersal of finely dividedparticles of naturally occurring waters or brines. These emulsions areoften extremely stable and will not resolve on long standing. It is tobe understood that water-in-oil emulsions may occur artificiallyresulting from any one or more of numerous operations encountered invarious industries. The emulsions obtained from producing wells and fromthe bottom of crude oil storage tanks are commonly referred to as cutoil, emulsified oil, bottom settlings, and B's-1,

One type of process involves subjecting an emulsion of the water-in-oiltype to the action of a demulsifying agent of the kind hereinafterdescribed, thereby causing the emulsion to resolve and stratify into itscomponent parts of oil and water or brine after the emulsion has beenallowed to stand in a relatively quiescent state.

Still another type of process involves the use of a demulsifying agentof the kind hereinafter described in refinery desalting operations. Inthe refining of many crude oils a desalting operation is necessary inorder to prevent the accumulation of large deposits of salt in thestills and to prevent corrosion resulting from the decomposition of suchsalts under high still temperatures. In a typical desalting installationto of fresh water is added to the crude oil charge stock and emulsifiedtherein by means of a pump or through a differential pressure valve. Ademulsifying agent is added and the treated oil permitted to stand in aquiescent state for relatively short periods of time allowing thesalt-laden water to stratify, whereupon it is bled off to wasteresulting in 90% to 98% removal of salt content. This operation iscarried out continuously as contrasted with batch treating.

One object of the invention is to provide a novel and economical processfor resolving emulsions of the character referred to into theircomponent parts of oil and water or brine.

Another object is to provide a novel reagent which is water-wettable,interfacial and surface-active in order to enable its use as ademulsifier or for such uses where surface-active characteristics arenecessary or desirable.

The treating agents employed in accordance with this invention can bedescribed as an addition product (or Patented Aug, 18, 1959 ICC acompound from the group consisting of aldehydes and ketones and analiphatic hydroxy compound containing a primary hydroxyl group, saidaddition product being further characterized by having a structurecontaining at least one interiorly located oxymethylene group to whichis linearly attached at least one larger polyoxyalkylene chain and atleast one aliphatic chain from the group consisting of aliphatichydrocarbon chains, aliphatic oxyhydrocarbon chains, N-hydrocarbonchains and mixtures of these chainsin the same molecule, with thefurther proviso that the average molecular weight attributable tooxyalkylene groups in said addition product is at least 1000 and thecombined weight of oxyalkylene groups from the class consisting ofoxymethylene and oxyethylene does not exceed the combined weight of theremainder of the molecule by a weight ratio greater than 4:1. Usuallythe addition products employed for the purpose of the invention have anaverage molecular weight not exceeding 20,000 but it is possible in somecases for the molecular weight to be much higher, for example, up to180,000.

If said addition product is prepared by the addition of a diol toformaldehyde the resultant addition product can be called a formal andthe terminal groups of the linear chain will be hydroxy groups. On theother hand, if a monoether of a diol is reacted with formaldehyde, theterminal groups of the resultant formal will be ether groups. If aformal diol is esterified one or both terminal groups will be estergroups. If a dicarboxy acid is used in the esterification the terminalgroups can be carboxy groups. If such terminal carboxy groups areneutralized the terminal groups are carboxy salt groups. If an aminesalt is used in the neutralization and the product is heated to amideforming temperatures the terminal groups are carboxy amide groups.

Where the oxymethylene groups and the groups derived from the hydroxycompound linked thereto do not recur in the linear chain the resultantaddition product can be described as monomeric. Where the oxymethylenegroups and the groups derived from the hydroxy compound linked theretorecur in the linear chain the resultant addition product is polymeric.In order for a monomeric addition product to be suitable for thepractice of the invention the initial oxyalkylene-containing hydroxycompound must have a relatively high molecular weight. Polymericaddition products suitable for the practice of the invention are readilyprepared, for example, by reacting a polyoxyalkylene diol such as apolyoxypropylene glycol having a molecular weight of at least 400 withformaldehyde until the total molecular weight of the oxyalkylene groupsexceeds 1000. It will be understood that the addition products employedin the practice of the invention can be cogeneric mixtures.

For the purpose of the invention where the composition employed is apolyoxyalkylene diol (or an ester, ether, or amine addition productthereof) having at least one interiorly located oxymethylene group andthe remainder of the oxyalkylene groups are higher oxyalkylene groups,it is preferable that the combined weight of the hydrophilic oxyalkylenegroups, namely, oxymethylene, and oxyethylene, does not exceed theweight of higher oxyalkylene groups by a weight ratio greater than 4:1.The weight ratio of such hydrophilic groups to such higher oxyalkylenegroups is preferably within the range of 4:1 to 1:9.

The addition products preferably employed in the practice of thisinvention may be represented by the structural formula HO C,,H ,,O ,OCEO] y (C H OHH wherein E is hydrogen or an alkyl or aryl radical, n is aninteger equal to 2 or more, and may have several values in the samecompound, and x and y are one or more. Where x and y are 2 or more theproducts are polymers. Such compounds are thus seen to includepolyoxyalkylene diols, in the polyoxyalkylene chain of which appears atleast one oxymethylene (or substituted oxymethylene) group, and in whichthere are also other (larger) oxyalkylene groups. By these largeroxyalkylene groups is meant oxyalkylene groups which are notoxymethylene or substituted oxymethylene groups. Examples of these largeoxyalkylene groups are oxyethylene (OCH CH oxypropyleue (-CH CH and-0CH2CH1CH:)

oxybutylene (-0 CH H (|7H-, 0 CH1CHCHT- CH CH3 -OCH CH;OH CH-, OCH, CH,

CH; H3

and O CHZCH;

and oxyalkylenes of greater number of carbons such as oxypentamethylene,oxyhexamethylene, oxydecamethylene and higher homologues. The largeroxyalkylene groups present in the polyoxyalkylene chain may all be thesame, or they may be different, so that several are present in the samechain. When the larger oxyalkylene groups are not all the same, they mayoccur in the chain in various proportions and in a regular or irregularsequence, with respect to each other. The term mixture is used hereingenerically to cover both a regular and an irregular sequence.

To illustrate the different types of end products contemplated for usein the practice of the invention there may be mentioned:

(a) Condensation products of aldehydes and ketones either simultaneouslyor successively with two types of polyhydric alcohols, viz., (1) thosein which primary hydroxyl groups are connected by a hydrocarbon chainand (2) those in which primary hydroxyl groups are connected by anoxyalkylene chain, e.g., condensation products of: formaldehyde withpentane diol 1,5 and polyethylene glycol 600, or polyoxypropylene glycol2000, or polyoxyethylated polyoxypropylene glycol 35-4 (4 moles ofethylene oxide added to a polyoxypropylene glycol derived from 35 molesof 1,2-propylene oxide);

(b) Condensation products of aldehydes and ketones with polyoxyalkyleneglycols, e.g., condensation products of: formaldehyde with diethyleneglycol; formaldehyde with triethylene glycol; formaldehyde withnonaethylene glycol; formaldehyde with Polyethylene Glycols 200, 300,400 and/or 600; formaldehyde with Polyglycols P-400, P-750, and/orP-1200; formaldehyde with Carbowax 1000, 1500 and/or 1540; formaldehydewith mixtures of polyoxyethylene glycols (e.g., Polyethylene Glycols200, 300, 400 and 600, Carbowax 1000, 1500 and 1540) andpolyoxypropylene glycols (e.g., those having average molecular weightsof 400, 750, 1200, 2000 and 2800); formaldehyde with Ucon HDG 373, Ucon10 HDG 506, Ucon 10 HDG 700, Ucon 10 HDG 1682, Ucon 25 HDG 510, Ucon 25HDG 876, Ucon 25 HDG 1156; Ucon 25 HDG 2157; Ucon 40 HDG 499; Ucon 40HDG 1026; Ucon 40 HDG 1703; Ucon 40 HDG 2412; Ucon 75 H 1400; Ucon 75 H4900; Ucon 75 H 9150 and/or Ucon 75 H 90,000;

(0) Condensation products of aldehydes and ketones with ether alcoholshaving a terminal hydroxy group and a terminal ether group and anaverage molecular weight of at least 500, e.g., condensation productsof: formaldehyde and the cetyl ether of nonaoxyethylene glycol;formaldehyde and the dodecyl ether of nonaoxyethylene glycol;formaldehyde and the cetyl ether of a polyoxypropylene glycol having anaverage molecular weight of 1200; formaldehyde and the monophenyl etherof a polyoxypropylene glycol having an average molecular weightaldehyde) and ketones (e.g., acetone) with mixtures of aliphatic hydroxycompound initial reactants as disclosed under (a), (b) or (c), supra,and aliphatic monohydric alcohols, e.g., methanol, ethanol, isopropanol,butanol, cyclohexanol, 2-ethyl hexanol, dodecyl alcohol, tetradecylalcohol, hexadecyl alcohol, octadecyl alcohol and/or myricyl alcohol;

(e) Condensation products of aldehydes and ketones with amino alcoholsderived by the condensation or primary and/or secondary monoamines andalkylene oxides from the group consisting of ethylene oxide, 1,2-propylene oxide and mixtures of ethylene oxide and 1,2- propylene oxide,for example, condensation products of: formaldehyde and 50 HBA 607;formaldehyde and 50 HBA 1613; formaldehyde and 50 HBA 1776; formaldehydeand 50 HBA 2098; formaldehyde and 50 HDBA 588; formaldehyde and 50 HDBA1373; formaldehyde and 50 HDBA 2855; formaldehyde and condensationproducts of ethylene oxide and/or 1,2-propylene oxide with amylamine,diamylamine, ethylamine, diethylamine, cyclohexylamine,dicyclohexylamine, benzylamine, dibenzylamine, aniline and diphenylamine;

(f) Condensation products of aldehydes and ketones with amino alcoholshaving at least two terminal hydroxy groups derived by the condensationor primary and/or secondary polyamines with an alkylene oxide from thegroup consisting of ethylene oxide, 1,2-propylene oxide, and mixtures of1,2-propylene oxide and ethylene oxide, there being preferably 1 to 9parts of 1,2-propylene oxide per part of ethylene oxide, e.g., thecondensation product of formaldehyde with a condensation product of apolyamine such as ethylene diamine, diethylene triamine, triethylenetetramine, tetraethylene pentamine, dipropylene triamine, tripropylenetetramine, meta phenylene diamine, benzidine, or naphthylene diaminesand ethylene oxide, and/ or 1,2-propylene oxide;

(g) The monoand diesters obtained by esterifying any of the condensationproducts under (a), (b), (e) and (f) with polycarboxy organic acids,e.g., terephthalic, glycollic, phthalic, maleic, adipic, dilinoleicacids, succinic, itaconic and homologous acids and anhydrides thereof,the monoester being formed when the end product contains a free carboxygroup;

(h) The alkali metal, ammonium, and amino salts of the monoesters under(g) (e.g., of the primary and secondary amines listed under (e) and(f));

(i) The amides of the carboxylic monoesters of (g) derived by a reactioninvolving the elimination of water between the hydroxy portion of acarboxy group of one of said monoesters and a hydrogen atom of a primaryand/or secondary amino group of an amine, e.g., any of the primary andsecond amines listed under (e) and (f).

The structures of the foregoing compounds will be characterized by oneor more oxymethylene groups connected linearly to a plurality of (a)aliphatic hydrocarbon groups and having terminal hydroxy groups; (b)aliphatic oxyhydrocarbon (ether) groups and having terminal hydroxygroups; (0) and (d) aliphatic hydrocarbon or oxyhydrocarbon groups andhaving terminal ether groups; (e) aliphatic oxyhydrocarbon groups andhaving terminal secondary or tertiary amino groups; (f) aliphaticN-hydrocarbon (nitrogen atoms linearly connected by carbon atoms) andoxyhydrocarbon groups linearly connected and having terminal hydroxygroups; (g) aliphatic hydrocarbon, oxyhydrocarbon and/or N- hydrocarbongroups having terminal hydroxy groups esterified with polycarboxy acids(either partially or completely esterified); (h) aliphatic hydrocarbon,oxyhydrocarbon and/or N-hydrocarbon groups having terminal carboxy saltgroups; and (i) aliphatic hydrocarbon, oxyhydrocarbon and/ orN-hydrocarbon groups having terminal carboxy amide groups. The preferredtreating agents contain at least one oxymethylene group linearlyattached to oxyhydrocarbon chains wherein the oxyhydrocarbon groups areoxyethylene and oxy-1,2-propylene and the weight ratio of oxyethylene tooxy-1,2-propylene in the molecule is within the range of 3 :1 to 1:9.

If the initial hydroxy reactant is a polyhydric alcohol, it is esentialthat the hydroxy groups therein be spaced by at least five atoms becauseif the hydroxy groups are too close to each other there is a tendencytoward the formation of ring compounds by reaction between the hydroxygroups and the aldehydes or the ketones.

The oxymethylene group in the addition product is supplied by thealdehyde or ketone reactant. If formaldehyde is used, the oxymethylenegroup will be unsubstituted. If a higher aldehyde is employed, theoxymethylene group will be substituted, depending upon the aldehydeused. Thus, if acetaldehyde is employed, the substituent will be amethyl group. If acetone is used in making the addition product theoxymethylene group contains two methyl substituents. If a higheraldehyde, for example, butyraldehyde, is employed, the substituent groupon the oxymethylene group will be a propyl group. If the aldehydereactant is benzaldehyde, the substituent on the oxymethylene group willbe a phenyl group. In a similar manner, homologous aldehydes and ketonesproduce addition products with different substituents on theoxymethylene group.

Formaldehyde either in an aqueous solution called formalin or as solidtrioxane is preferably employed as one of the initial reactants becauseit forms compounds of high molecular weight when reacted with lowmolecular weight aliphatic polyhydric alcohols. Other aldehydes andketones do not react so readily and usually only form a dimer of thealiphatic alcohol. These other aldehydes and ketones can be usedprovided the aliphatic alcohol compound itself has a rather highmolecular weight so that the resultant product will have the necessaryhigh molecular weight.

The preferred reactants used to form the addition products areformaldehyde and polyoxyalkylene glycols containing 2 to 5 carbon atomsin their oxyalkylene groups. The oxyethylene group is relativelyhydrophilic and hence where the polyoxyalkylene glycol reacted with theformaldehyde contains all oxyethylene groups relatively high molecularweights must be attained in order to secure the best results in breakingwater-in-oil emulsions. Higher oxyalkylene groups such as those derivedfrom 1,2-propylene groups are more hydrophobic and where these groupsare present as the sole oxyalkylene groups in the polyoxyalkyleneglycol, the optimum results can be obtained with products having asubstantially lower molecular weight. Excellent results are obtained byusing as one of the reactants an aliphatic ether alcohol characterizedby a polyoxyalkylene group having different terminal groups connected todifferent carbon atoms, one of said terminal groups being a hydroxygroup and the other being either a hydroxy group or an ether group, andthe oxyalkylene groups being either 0Xy-1,2-propylone groups, oroxyethylene and oXy-1,2-propylene groups derived from at least 6 part of1,2-propylene oxide for each part of ethylene oxide by Weight.

The reaction between the aldehyde and the ketone, on the one hand, andthe aliphatic hydroxy compound on the other, is carried out in thepresence of a suitable catalyst either under dehydrating conditions or,alternatively, the aliphatic hydroxy compound can first be reacted withthe aldehyde or ketone and then the watei formed in the reaction can beremoved from the reaction zone. In the following discussion theproportion of the addition products will be illustrated by theemployment of formaldehyde as one of the reactants and a polyoxyalkyleneglycol as the other, but it will .be understood that the same reactionconditions are applicable to the employment of other aldehydes orketones, on the one hand, and other aliphatic hydroxy compounds, on theother hand.

It will be understood that while in discussing these reactions referenceis made to the use of formaldehyde, the formaldehyde may be supplied andpreferably is employed in the form of a compound which liberatesformaldehyde in situ in an anhydrous form. A preferred compound for thispurpose is trioxane which when heated in a substantially anhydroussystem in the presence of strong acids such as sulfuric, hydrochloricand phosphoric acids or acidic materials such as zinc chloride, ferricchloride or the like, is readily depolymerized to monomericformaldehyde. The formaldehyde produced in this way is extremelyreactive and enters readily into combination when the depolymerizationis carried out in the presence of the hydroxy compound capable ofreacting with the formaldehyde. (See Walker, Formaldehyde, secondedition, Monograph Series 120, Rheinhold Publishing Corporation, 1953,pages 152, 153.) Other polyoxymethylene compounds capable ofdepolymerizing to formaldehyde under the reaction conditions can beemployed as a source of formaldehyde. Paraformaldehyde may also be usedas a source of formaldehyde. The use of aqueous formaldehyde is usuallyundesirable because the condensation reaction itself involves theelimination of water and the use of a material initially containingwater requires the elimination of additional quantities of water.

The reaction between the glycol and the formaldehyde is preferablycarried out at moderate temperatures, for example, between 50 C. and C.,with or without a solvent as a diluent. To accelerate the reactionFriedel-Crafts catalysts are preferably employed, for example, aluminumchloride, ferric chloride, titanium tetrachloride, stannic chloride,borontrifiuoride, and acid compounds such as sulfuric acid, benzenesulfonic acid or acid cation exchangers containing strongly acidicgroups such as the sulfonated polymer of styrene and divinylbenzene,sulfonated phenol-formaldehyde resin, sulfonated coal or the like.

The reaction is preferably carried out under very strong dehydratingconditions facilitating the removal of water from the reaction mixture.In the practice of the invention two different methods have beenemployed effectively. In one case aromatic hydrocarbons, such asbenzene, toluene or xylene, which form azeotropes with water weredistilled from the reaction Zone. The water formed in the reaction wasthus continuously eliminated and very strong dehydrating conditionsexisted. In the second method the water was removed under vacuum using aslow stream of dry air to give the strong dehydrating conditionsnecessary. Other methods of preparation in which very strong dehydrationconditions exist are also suitable for the preparation of the compoundsof this invention.

In order to separate and collect the water formed in the reaction it isconvenient to carry out the reaction in benzene solution. The benzene isdistilled slowly and the Water distilling with the benzene is separated.The benzene is then returned to the reaction zone.. The water collectedis measured and the progress of the reaction can be followed in thisway. A convenient apparatus for carrying out this reaction consists of aDean-Stark moisture trap fitted with a reflux condenser and a roundbottom boiling flask. A tube full of a desiccant, such as calciumchloride, is preferably attached to the open end 7 of the refluxcondenser to prevent the condensation of the moisture from theatmosphere.

By way of illustrating the effectiveness of the products contemplated bythis invention the method of testing their efficiency in bottle testswill be described and examplary date given.

Example I Field bottle tests were made on samples of emulsified oiltaken from the Dominguez Hills field in California. A sample grind-outshowed that these emulsions contained about 41 parts of water per 100parts of emulsion. A wash tank system was being used in this field.

One hundred (100) cc. samples were taken and placed in conventionalfield test bottles. A finding ratio test indicated a treating ratio of0.09 cc. of a 10% solution of the treating chemical was required for 100cc. of sample.

Every effort was made to maintain conditions com parable to thosepresent in a full scale plant treatment.

The test chemical was added to the samples in the test bottles and eachbottle was agitated by shaking it 200 times at 90 F. The compositions inthe test bottles were then allowed to settle and were tested for waterdrop at predetermined periods of time.

After the first agitation each sample was shaken an additional 100 timesat a temperature of 90 F. After agitation at said temperatures thesamples were allowed to stand to permit settling and stratification ofthe water and again tested for water drop.

A condensation product of pentane diol-1,5, polyethylene glycol 600, andtrioxane was tested in the manner described above. Twenty minutes afterthe bottles were shaken 200 times, 25 out of the 41 parts of waterseparated, The bottles were then shaken another 100 times and 60 minutesafter the first agitation of the bottles 39 out of the 41 parts of waterhad separated. On standing approximately 12 hours all of the water hadseparated.

The composition used in this example was prepared as follows:

In a reaction vessel equipped with thermometer, stirrer and means forrefluxing solvent with provisions for trapping any water which forms inthe course of the reaction, there was mixed 104 parts pentane diol-1,5,30 parts trioxane, 1 part ferric chloride and 150 parts of benzene. Thereactants were heated together with agitation until the water ofreaction started distilling over. At that point the source of heat wasremoved and 100 parts of polyethylene glycol 600 and parts of trioxanewere added. The heating was resumed and continued until a total of 21parts of water had been secured. The temperature of this reaction variedbetween 81 and 92 C. with the water being secured in about 18 hours.

Example II The procedure was the same as in Example I except that thesample bottles were shaken 200 times at atmospheric temperatures andthen 100 times at 100 F. The treating ratio was 0.20 cc. of a solutionof the treating chemical per 100 cc. of sample. 20 minutes after thecold agitation a product made by reacting trioxane with polyethyleneglycol 600 and polypropylene glycol 750 caused out of the 41 parts ofwater to separate. Thereafter the samples were given hot agitation and60 minutes later all of the water had separated.

The composition employed as a treating agent in this example wasprepared as follows:

In equipment similar to that described in Example I, 100 parts ofpolyethylene glycol 600, 125 parts of polypropylene glycol 750, 10 partsof trioxane, 1 part of ferric chloride and 100 parts of benzene wereheated together with agitation until a total of 8.4 parts of waterf9osrrngd in 4 /2 hours at a temperature between 92 and Example Ill Theprocedure was the same as that described in Example I except that theemulsified oil was taken from a field at Signal Hill, California, usingthe flow line type of system. The test bottles were shaken 200 times atatmospheric temperatures and times at a temperature of F. The emulsifiedoil contained 42 parts of water per 100 cc. sample. The treating ratiowas 0.15 cc. of a 10% solution of the treating agent. Thirty minutesafter cold agitation the product described in Example II caused theseparation of 36 parts of water. After hot agitation and 95 minutes fromthe beginning of the test 40 parts out of the 42 parts of water in theemulsion had separated.

In a similar manner this emulsion was treated with a composition made bycondensing trioxane with polyethylene glycol 600 and polypropyleneglycol 750. After cold agitation this composition caused the separationof 39 parts of water approximately 30 minutes from the beginning of thetest. After hot agitation the same composition caused the separation of40 parts of water approximately 95 minutes from the beginning of thetest. Approximately 41 parts of water separated after 3% hours from thebeginning of the test.

The last named composition was prepared as follows:

In equipment similar to that employed in Example I, 60 parts ofpolyethylene glycol 600, parts of polypropylene glycol 750, 9 parts oftrioxane, 1 part of ferric chloride and 100 parts of benzene were heatedtogether with stirring until a total of 6.8 parts of water had beenremoved from the reaction. This required 6 hours at a temperature of 92to 98 C.

Example IV In equipment similar to that employed in Example I, 100 partsof polyethylene glycol 600, 200 parts of polypropylene glycol 1200, 10parts of trioxane, 2 parts of ferric chloride, and 100 parts of benzenewere heated until a total of 7.4 parts of water were secured from thereaction. This required 7 /2 hours at a temperature of 98 to 107 C.

This composition was tested in the same manner as described in ExampleIII with essentially the same results as those described for the lastnamed composition in Example III.

Example V In equipment similar to that employed in Example I, 36 partsof polyethylene glycol 600, parts of polypropylene glycol 750, 9 partsof trioxane and 1 part of ferric chloride and 100 parts of benzene wereheated with stirring until a total of 6.7 parts of an aqueous distillatehad been secured. This required 10 hours at a temperature of 95 to 102C.

This composition was tested as described in Example III and caused theseparation of 32 out of the 42 parts of water to occur in 30 minutesafter the start of the test and before hot agitation. After hotagitation and 95 minutes from the start of the test 40 out of the 42parts of water had separated.

Example VI The procedure was the same as that described in Example Iexcept that the emulsified oil was taken from a field at Signal Hill,California, using the flow line type of system. The samples were shaken200 times at atmospheric temperatures and 100 times at a temperature of130 F. The treating ratio was 0.08 cc. of a 10% solution of the treatingagent per 100 cc. sample of emulsified oil.

The treating agent employed in this example was a condensation productof trioxane with polyethylene glycol 400 and polypropylene glycol 750.Before hot agitation this composition caused 40 parts out of the 42parts of water to separate. The same amount separated after hotagitation and 85 minutes from the beginning of the test. The emulsionbreaking properties of this composition were therefore outstanding.

The composition employed in this example was prepared as follows:

In equipment similar to that employed in Example I 40 parts ofpolyethylene glycol 400, 150 parts of polypropylene glycol 7 50, 9 partsof trioxane, 1 part of ferric chloride and 100 parts of benzene wereheated with stirring until a total of 5.8 parts of water had beensecured which required 6 hours at a temperature of 92 to 106 C. Thereaction product was cooled and an additional 9 parts of trioxane and 50parts of benzene were added and reheated to lose an additional 1.5 partsof aqueous distillate. This latter portion of the reaction required 8hours at a temperature of 93 to 104 C.

Example VII In equipment similar to that employed in Example I, 60 partsof polyethylene glycol 600, 150 parts of polypropylene glycol 750, 9parts of trioxane, 1 part of ferric chloride, and 100 parts of benzenewere heated with stirring until 6 parts of an aqueous distillate hadbeen secured which required approximately 7 hours at a temperature of 93to 113 C. The reaction product was cooled and an additional 9 parts oftrioxane and 50 parts of benzene added. Heating was resumed until anadditional 1.4 parts of aqueous distillate was secured. This phase ofthe reaction required approximately 4 hours at a temperature of 95 to101 C.

The composition prepared as described above was tested as described inExample VI with essentially the same results. This composition was alsooutstanding.

Example VIII The procedure was the same as that described in Example Iexcept that the emulsified oil was taken from the Wilmington field,California. The temperature of hot agitation was 150 F. and the samplescontained 22 cc. of water per 100 cc. of emulsion before hot agitation.A composition made by condensing trioxane with polyethylene glycol 400and polypropylene glycol 2000 caused 16 out of the 22 parts of water toseparate. After hot agitation and 3 hours from the start of the test 21out of the 22 parts of water had separated.

The treating agent employed in this example was prepared as follows:

In equipment similar to that employed in Example I, 60 parts ofpolyethylene glycol 400, 152 parts of polypropylene glycol 2000, 7 partsof trioxymethylene, 1 part of ferric chloride and 150 parts of benzenewere heated with stirring until a total of 4.6 parts of an aqueousdistillate had been secured which required 6 hours at a temperature of87 to 96 C. The intermediate reaction product was cooled and anadditional 7 parts of trioxymethyl ene added and heating continued tosecure an additional 1.8 parts of aqueous distillate. This seconddistillation required hours at a temperature of 95 to 101 C.

Example IX In equipment similar to that employed in Example I, 40 partsof polyethylene glycol 600, 164 parts of polypropylene glycol 1000, 7.2parts of trioxane, 1 part ferric chloride and 150 parts benzene wereheated with stirring until a total of 4.2 parts of water had distilledover. The reaction mass was cooled and an additional 7.2 parts oftrioxane added. The mass was reheated until an additional 2.2 parts ofaqueous distillate had been collected. This latter reaction requiredapproximately 3 hours at a temperature of 86 to 88 C.

The procedure of testing was the same as described in Example VIII butthe product was not as efiective as that described in Example VIII.

Example X In equipment similar to that employed in Example I, 60 partsof polyethylene glycol 600, 150 parts of polypropylene glycol 750, 9parts of trioxane, 2 parts of ferric chloride and 150 parts of benzenewere heated with stirring until a total of 6.2 parts of an aqueousdistillate had been secured. The reaction mass was cooled to permit theaddition of an additional 9 parts of trioxane. Heating was then gentlyresumed to secure an additional 1.3 parts of aqueous distillate.

This product was tested in the general manner described in the previousexamples and found to be effective in breaking water-in-oil emulsions.

Example XI In equipment similar to that employed in Example I, 150 partsof polypropylene glycol 750, 9 parts of trioxane, 3 parts of aluminumchloride, and 150 parts of benzene were heated together with stirringuntil 1.8 parts of aqueous distillate had been secured. Thisdistillation required 2 hours at a temperature of 85 to 89 C. Thereaction mass was cooled and 60 parts of polyethylene glycol 600 wasadded and the heating continued until 1.8 parts of Water had beensecured in 2 /2 hours between 90 and 92 C. The reaction mass was againcooled to permit the addition of 9 parts of trioxane. This required areaction time of 7 hours at a temperature between 92 and 93 C.

This product was tested in the general manner described in the previousexamples and found to be effective in breaking water-in-oil emulsions.

Example XII In equipment similar to that employed in Example I, parts ofpolyethylene glycol 600, parts of polypropylene glycol 750, 15 parts ofacetaldehyde, 1 part of ferric chloride and 100 parts of benzene wereheated together with agitation until a total of 8.4 parts of waterformed in 4% hours at a temperature between 92 and 98 C.

This product was tested in the general manner described in the previousexamples and found to be effective in breaking water-in-oil emulsions.

Example XIII In equipment similar to that employed in Example I, 60parts of polyethylene glycol 600, parts of polypropylene glycol 750, 15parts of acetaldehyde, 1 part ferric chloride, and 100 parts of benzenewere heated with stirring until 6 parts of an aqueous distillate hadbeen secured which required approximately 7 hours at a temperature of 93to 113 C. The reaction prodnot was cooled and an additional 15 parts ofacetaldehyde and 50 parts of benzene added. Heating was resumed until anadditional 1.4 parts of aqueous distillate was secured. This phase ofthe reaction required approximately 4 hours at a temperature of 95 to101 C.

This product was tested in the general manner described in the previousexamples and found to be effective in breaking water-in-oil emulsions.

Example XIV In equipment similar to that employed in Example I, 320parts of polyethylene glycol 400, 814 parts of polypropylene glycol2000, 5 parts of ferric chloride, 36 parts of formaldehyde as anapproximately 40% aqueous solution, and 400 parts of benzene were heatedwith stirring to obtain 23.5 parts of an aqueous distillate which wassecured at a temperature of 93 to 101 C. in approximately 7 hours. Thereaction mass was cooled to permit the addition of an additional 36parts of formaldehyde as an approximately 40% aqueous solution and 5parts of ferric chloride. The reaction mass was heated until 5.9 partsof an aqueous distillate formed at a temperature of 98 C. in a period of1 hour.

This product was tested in the general manner de scribed in the previousexamples and found to be effective in breaking water-in-oil emulsions.

Polyglycol P-400 m 20 Trioxymethylene gm 1.5 Aluminum chloride(anhydrous) gm .2 Benzene l 50 Heating was started with a small flame at:00 a.m. distillate containing water started to distill into the waterseparating chamber at about 11:30 am. Distillation was continued until.9 ml. (.05 mole) of water had been collected; about 2:30 to 3.00 pm.one gram of anhydrous potassium acetate was added and the heatingcontinued for an additional minutes. The solution was filtered and thebenzene was removed under vacuum. The product was a brown viscousliquid.

This product was tested in the general manner described in the previousexamples and found to be effective in breaking water-in-oil emulsions.

Example XVI In equipment similar to that employed in Example I, 850parts of Ucon 50 HB 660, 65 parts of 2-ethylhexanol, 15 parts oftrioxymethylene, 10 parts aluminum chloride and 200 parts of benzenewere heated with stirring until 9.5 parts of water of reaction wereobtained. This was secured in 3.5 hours at a temperature range of 85 to104 C.

This product was tested in the general manner described in the previousexamples and found to be effective in breaking water-in-oil emulsions.

Example XVII In equipment similar to that employed in Example I, 104parts of pentane diol-1,5, 44 parts of acetaldehyde, 3 parts of aluminumchloride and 150 parts of benzene were heated until water of reactionbegan to distill out. At that point the source of heat was removed and100 parts of polyethylene glycol 600 and 5 parts of trioxane added. Theheating was resumed until a total of 21 parts of an aqueous distillatehad been secured at a temperature of 81 to 92 C. in about 18 hours.

This product was tested in the general manner described in the previousexamples and found to be eifective in breaking water-in-oil emulsions.

In the foregoing description the so-called polyethylene glycols followedby a number are the trade names for products made by Carbide and CarbonChemicals Corporation having the general formula:

HOCH (CH OCH CH OH Polyethylene glycols 200, 300, 400 and 600 are allviscous light colored somewhat hygroscopic liquids of low vapor pressurehaving molecular weights from 200 to 700, thus polyethylene glycol 400has an average molecular weight between 380 and 420 and is chiefly amixture of nonaoxyethylene glycol [HO (CH CH O H] and octaoxyethyleneglycol [HO (CH CH O 1-1] The Carbowax compounds are polyoxyethyleneglycols which are wax-like solids having a molecular weight about 1000.In the foregoing description the number following the name Carbowaxindicates the approximate molecular weight except in the case ofCarbowax 1500. Carbowax 1500 is a blend of equal parts of polyethyleneglycol 300 and Carbowax 1540 and has an average molecular weight between500 and 600.

The polyglycol P compounds are commercial polyoxypropylene glycols madeby Dow Chemical Company.

12 The number following the letter P signifies the aver age molecularweight of the glycols present in the mixture. For example, polyglycolP-400 consists mainly of a mixture of hexaoxypropylene glycol CH; [H0(omoHonH and heptaoxypropylene glycol CH [HO(GH2(IJHO)1H The Ucon 75-Hcompounds are polyoxyalkylene glycols made by Carbide and CarbonChemicals Corporation in which the oxyalkylene groups consist ofoxyethylene and oxy-1,2-propylene groups in the same molecule. Thecompounds of this class designated 75-H contain a weight ratio ofethylene oxide to 1,2-propylene oxide of about 3:1. Among the mixedoxyethylene-oxypropylene glycols which may be reacted with substantiallyequal molecular proportions of formaldehyde in accordance with theinvention are: Ucon 75 H 4900, Ucon 75 H 1400, Ucon 75 H 9150 and Ucon75 H 90,000. Polyoxyalkylene glycols in which the oxyalkylene groupsconsisting of oxyethylene and 1,2-oxypropylene groups in an approximateweight ratio of 3:1, of 1:1, and of 1:9 are also suitable for reactionwith an aldehyde in accordance with the invention. So far as the genericaspects of the invention are concerned the relative proportions ofoxyethylene and oxypropylene groups in a given oxyalkylene glycol arenot critical but it will be understood that different types of productsare obtained depending upon the particular polyoxyalkylene glycolemployed as a starting material.

The Ucon HDG compounds are high molecular weight glycols derived fromdiethylene glycol by the addition of ethylene oxide and 1,2-propyleneoxide thereto. The number before the HDG indicates the percent ofethylene oxide, the remainder of the polyoxyalkylene groups beingderived from 1,2-propylene oxide. The number following the HDG indicatesthe viscosity SUS at F.

The Ucon HB compounds are addition products of ethylene oxide and1,2-propylene oxide to butyl alcohol. The number ahead of the HBindicates the percentage of ethylene oxide, the remainder of thepolyoxyalkylene groups being derived from 1,2-propylene oxide. Thus,Ucon 50 HB 660 contains ethylene oxide and 1,2-propylene oxide in aweight ratio of 1:1 and has a molecular weight of about 1700. The numberfollowing the HB indicates the viscosity SUS at 100 F.

The Ucon LB compounds are derived from butyl alcohol and 1,2-propyleneoxide. Thus, Ucon LB 1145 is the monobutyl ether of a polyoxypropyleneglycol having a viscosity at 100 F. of 1145 SUS. This composition has amolecular weight of approximately 1700.

The Ucon HTD compounds are similar to the HB compounds except that theyare derived from dodecyl alcohol instead of butyl alcohol.

The Ucon HM compounds are similar to the HB compounds except that theyare derived from methyl alcohol instead of butyl alcohol.

The Ucon HBA compounds are addition products of ethylene oxide and1,2-propylene oxide with butylamine.

The Ucon HDBA compounds are addition products of ethylene oxide and1,2-propylene oxide with dibutylamine. The number in front of the HDBAindicates the percentage of ethylene oxide, the remainder being1,2-propylene oxide. The last number indicates the viscosity SUS at 100F.

The demulsifying compositions of the present invention are preferablyemployed in the proportion of one part of demulsifying agent to from10,000 to 100,000 parts of emulsion either by adding the concentratedproduct directly to the emulsion or diluting with a vehicle in thecustomary manner.

Among the suitable hydrocarbon vehicles which can be employed asdiluents is sulfur dioxide (S extract. This material is a by-productfrom the Edeleanu process of refining petroleum in which the undesirablefractions are removed by extraction with liquid sulfur dioxide. Afterremoval of the sulfur dioxide a mixture of hydrocarbons, substantiallyaromatic in character, remains which is designated in the trade as S0extract. Examples of other suitable hydrocarbon vehicles are Gray Towerpolymers, toluene, xylene, gas oil, diesel fuel, bunker fuel and coaltar solvents.- The above cited examples of solvents are adaptable toazeotropic distillation as would also be any other solvent which isimmiscible with water, miscible with the reacting mass and has a boilingpoint or boiling range in excess of the boiling point of water.

The products prepared in accordance with the invention are very usefulin breaking petroleum emulsions, especially those in which the oil isparafiinic or parafiinicnaphthenic, and are suitable for use in breakingwaterin-oil petroleum emulsions in the Mid-continent oil fields,

including Oklahoma, Illinois, Kansas, the Gulf coast, Louisiana,Southwest Texas and Califoi-nia.

The term an oxymethylene group unless modified by the wordsunsubstituted or substituted is intended to cover generically the groupwhere A and B may be hydrogen or carbon radicals, e.g., alkyl or arylradicals. An unsubstituted oxymethylene group is one in which both A andB are hydrogen atoms. A substituted methylene group is one in which A orB or both is a carbon radical in which a carbon atom is linked to themain methylene group.

The invention is hereby claimed as follows:

1. A process of breaking water-in-oil emulsions which comprises treatingsuch emulsions with an addition product of a compound from the groupconsisting of aldehydes and ketones and an aliphatic hydroxy compoundcontaining a primary hydroxyl group, said addition product being furthercharacterized by having a structure containing at least one interiorlylocated oxymethylene group to which is linearly attached at least onelarger polyoxyalkylene chain and at least one aliphatic chain from thegroup consisting of aliphatic hydrocarbon chains, aliphaticoxyhydrocarbon chains, N-hydrocarbon chains and mixtures of said chainsin the same molecule, with the further proviso that the averagemolecular weight attributable to oxyalkylene groups in said additionproduct is at least 1000 and the combined weight of oxyalkylene groupsfrom the class consisting of oxymethylene and oxyethylene does notexceed the combined weight of the remainder of the molecule by a weightratio greater than 4: 1.

2. A process of breaking water-in-oil emulsions which comprises treatingsuch emulsions with an addition product of a compound from the groupconsisting of aldehydes and ketones and an aliphatic hydroxy compoundcontaining a primary hydroxyl group, said addition product being furthercharacterized by having a structure containing at least one interiorlylocated oxymethylene group to which is linearly attached at least onelarger polyoxyalkylene chain and at least one aliphatic chain from thegroup consisting of aliphatic hydrocarbon chains, aliphaticoxyhydrocarbon chains, N-hydrocarbon chains and mixtures of said chainsin the same molecule, with the further proviso that the averagemolecular weight attributable to oxyalkylene groups in said additionproduct is at least 1000, the combined weight of oxyalkylene groups fromthe class consisting of oxymethylene and oxyethyl- 14 ene does notexceed the combined weight of the remainder of the molecule by a Weightratio greater than 4: 1, and the total average molecular weight of saidaddition product does not exceed 20,000.

3. A process of breaking water-in-oil emulsions which comprises treatingsuch emulsions with an addition product of formaldehyde and an aliphatichydroxy compound containing a primary hydroxyl group, said additionproduct being further characterized by having a structure containing atleast one interiorly located oxymethylene group to which is linearlyattached atleast one larger polyoxyalkylene chain and at least onealiphatic chain from the group consisting of aliphatic hydrocarbonchains, aliphatic oxyhydrocarbon chains, N-hydrocarbon chains andmixtures of said chains in the same molecule, with the further provisothat the average molecular weight attributable to oxyalkylene groups insaid addition product is at least 1000 and the combined weight ofoxyalkylene groups from the class consisting of oxymethylene andoxyethylene does not exceed the combined weight of the remainder of themolecule by a weight ratio greater than 4:1.

4. A process as claimed in claim 3 in which said addition product is adiol.

5. A process as claimed in claim 3 in which said addition product is anester of a diol.

6. A process as claimed in claim 3 in which said addition product is anether of a diol.

7. A process as claimed in claim 3 in which said addition product is anamine addition product of a diol.

8. A process of breaking water-in-oil emulsions which comprises treatingsuch emulsions with an addition product of formaldehyde and apolyoxyalkylene aliphatic hydroxy compound containing a primary hydroxylgroup, said .addition product being further characterized by having astructure containing at least one interiorly located oxymethylene groupto which is linearly attached at least one larger polyoxyalkylene chainand at least one aliphatic chain containing oxypropylene groups, withthe further proviso that the average molecular weight attributable tooxyalkylene groups in said addition product is at least 1000, thecombined weight ratio of oxyalkylene groups from the class consisting ofoxymethylene and oxyethylene to the combined weight of higheroxyalkylene groups is within the range of 4:1 to 1:9, and the averagemolecular weight of said addition product does not exceed 20,000.

9. A process of breaking water-in-oil petroleum emulsions whichcomprises treating such emulsions with an addition product offormaldehyde and a polyoxypropylene glycol, the average molecular weightattributable to oxyalkylene groups in said addition product being atleast 1000.

10. A process of breaking water-in-oil petroleum emulsions whichcomprises treating such emulsions with an addition product offormaldehyde, a polyoxyethylene glycol and a polyoxypropylene glycol,the average molecular weight attributable to oxyalkylene groups in saidaddition product being at least 1000, the combined Weight ratio ofoxyalkylene groups from the class consisting of oxymethylene andoxyethylene to the combined weight of oxypropylene groups being withinthe range of 4:1 to 1:9 and the average molecular weight of saidaddition product not exceeding 20,000.

References Cited in the file of this patent UNITED STATES PATENTS2,330,474 De Groote Sept. 28, 1943 2,375,537 De Groote May 8, 19452,403,343 De Groote July 2, 1946

1. A PROCESS OF BREAKING WATER-IN-OIL EMULSIONS WHICH COMPRISES TREATINGSUCH EMULSONS WITH AN ADDITION PRODUCT OF A COMPOUND FROM THE GROUPCONSISTING OF ALDEHYDES AND KETONES AND AN ALIPHATIC HYDROXY COMPOUNDCONTAINING A PRIMARY HYDROXYL GROUP, SAID ADDITION PRODUCT BEING FURTHERCHARACTERIZED BY HAVING A STRUCTURE CONTAINING AT LEAST ONE INTERIORLYLOCATED OXYMETHYLENE GROUP TO WHICH IS LINEARLY ATTACHED AT LEAST ONELARGER POLYOXYALKYLENE CHAINS, N-HYDROCARBON CHAINS, ALIPHATICOXYHYDROCARBON CHAINS, N-HYDROCARBON CHAINS AND MIXTURE OF SAID CHAINSIN THE SAME MOLECULE, WITH THE FURTHER PROVISO THAT THE AVERAGEMOLECULAR WEIGHT ATTRIBUTABLE TO OXYALKYLENE GROUPS IN SAID ADDITIONPRODUCT IS AT LEAST 1000 AND THE COMBINED WEIGHT OF OXYALKYLENE GROUPSFROM THE CLASS CONSISTING OF OXYMEHTYLENE AND OXYETHYLENE DOES NOTEXCEED THE COMBINED WEIGHT OF THE REMAINDER OF THE MOLECULE BY A WEIGHTRATTIO GREATER THAN 4:1